In the manufacturing process of a display panel, it is a common film preparation method to form films (for instance, a photoresist layer, a gate insulating layer, a passivation layer and a planarization layer) in the display panel by coating via a coating apparatus.
Taking the adoption of a slit type coating apparatus (slot die coating apparatus) as an example, the basic use process of the coating apparatus includes: cleaning the coating apparatus; afterwards, providing a coating liquid to a coating liquid nozzle of the coating apparatus; and then, preparing a film by utilization of the coating liquid nozzle of the coating apparatus. In the process of preparing the film, the coating liquid nozzle of the coating apparatus moves along a surface of a substrate to be coated from one side of the substrate to the other opposite side of the substrate at a predetermined speed, and meanwhile, a coating opening of the coating liquid nozzle discharges a film material at a predetermined speed; and along with the movement of the coating liquid nozzle, the film material is coated to the surface of the substrate to form a corresponding film.